Turning a near no-hitter by Mike Pelfrey into their third loss to Washington in the past four games was so frustrating for the Mets that signs of a clubhouse fracture were evident afterward.

Outspoken closer Billy Wagner barked at reporters for interviewing him instead of center fielder Carlos Beltran and first baseman Carlos Delgado, otherwise known as the two primary culprits in the Mets’ nearly season-long hitting funk.

“Can somebody tell me why the [bleep] the closer is being interviewed and I didn’t even play? And why they’re over there not being interviewed?” Wagner bellowed as he pointed to the lockers of Beltran and Delgado. “Oh, I got it. They’re [bleeping] gone. [Bleeping] shocker.”

He was mistaken about Beltran, who had made himself available to reporters, but Wagner indicated to ESPN 1050 after the game that accountability on the part of two of the team’s key hitters is going to be addressed.

“That’s something that will be reconciled tomorrow,” Wagner told the station.

Wagner’s outburst was far from the only sign of unrest at Shea. Not only did fans rain down boos on Randolph for the second game in a row after he lifted Pelfrey in the eighth, but left fielder Moises Alou – one of the Mets’ best hitters – wondered openly about being given the day off by his manager.

Grumbling also greeted three crucial plays that led directly to the Mets’ first shutout loss of the season: Luis Castillo failing to run hard on a dropped fly ball in the third inning, Jose Reyes getting thrown out at third trying to go from first to third on a sacrifice bunt in the eighth and Beltran getting doubled off third to end the game.

Combine those plays with the Nos. 3-6 hitters in the Mets’ lineup going a combined 1-for-15, and it was easy to understand the palpable tension in the locker room.

This was no way to go into the Subway Series that starts tonight at Yankee Stadium.

“We’re not playing the way we should be playing,” said Alou, who was poised to pinch hit in the ninth until Beltran – running on contact – was doubled off on a Delgado liner to first to end things.

Reactions like that are to be expected when the Mets fail to get a runner past second in seven innings against Nationals starter Jason Bergmann, who had just been recalled from the minors and was sporting an 11.68 ERA. That, combined with a game-saving catch by Nationals left fielder Willie Harris in the ninth was enough to make a hard-luck loser of Pelfrey (2-4), who took a no-hitter into the seventh before Aaron Boone led off with a single. Pelfrey lasted one more inning, allowing the game’s only run before being lifted after 100 pitches.

“It’s tough to see Pelfrey go out there and throw the ball the way he did and get a loss, but that’s the way the ball rolls sometimes,” said David Wright, who went 0-for-4.

Wright was so upset by his day that he flung his bat and helmet in frustration after stranding two runners with a weak pop fly to short in the fifth. Based on Wagner’s comments, the Mets could use a few more players who care like that.

“We’re just not getting it done,” Wagner said. “The effort’s there, but we’re just not earning our money.”